This invention relates to a gear box with integral differential for use in automotive vehicles and more particularly is designed for use in compact vehicles of the air transportable type.
Gear boxes with integral differential are well known. They are normally constituted of a housing which encloses three spaced, parallel shafts referred to, respectively, as the reduction control shaft (lay shaft), the upper or driving shaft, and the differential shaft. The differential shaft is axially movable and its longitudinal displacement is effected by a gear shift lever having a fork engaged with an idler gear which provides a mechanical connection between the differential shaft and the driving shaft which is coupled to the vehicle transmission. The upper or driving shaft receives an idler gear which is axially movably splined upon said shaft and is capable of being selectively engaged either with the teeth of the ring gear which is a gear of the same modulus to provide direct drive (without reduction) or with the teeth of a second gear of smaller modulus called the reduction gear. The direct drive gear or the reduction gear energized by the idler thus imparts different speeds to the differential gear borne by the third or differential shaft. The differential gear provides, by the action of a differential gear system which consists of planetary and ring gears, the rotation of the differential shaft itself. The later consists of two parts which are susceptible of being coupled by a system of locking dogs under the control of a control handle. Each part of the differential shaft is connected to the forward and rear deck of the axles of the vehicle and are capable of rotating at the two different speeds.
This gear box, of known type and the integral differential, has the drawback of being massive and requires much space which makes it incompatible with the requirements imposed upon compact air transportable vehicles. This type of vehicle has rigorously limited dimensions to enable it to be loaded into a cargo plane. It must be designed and developed on the basis of mechanical components whose shape and size are specifically designed to conform to the mission of the vehicle.